And to complete the thread: A big shout out to Allan Stokes who finished the work that Simen Pedersen and I started before he got on board, and of course all other co-authors in the fantastic #Scandcam team!

Concluding, Norwegian mountain hares are experiencing a mismatch in their camouflage as a consequence of rapid snow cover declines. Future studies will have to show how this impacts survival and population dynamics.

Check out the full text @globalchangebio.bsky.social
doi.org/10.1111/gcb....

We also looked at the timing of the moult (2011-2018) relative to when the snow arrived or disappeared during two periods (1959-1966 and 2011-2018). It turned out that hares were mostly too late during autumn, and that they were better adapted to historic snow cover than to contemporary snow cover.

Maybe not surprisingly, the total number of days during which hares were mismatched compared to their surroundings (i.e. not camouflaged) was higher in places where the annual number of days with snow cover decreased the fastest. So mountain hares cannot keep up with the fast disappearance of snow.

We modelled mountain hare phenology to determine the coat colour (brown, white or moulting) for each location during each day of the year and linked this to high resolution data on snow cover to count the number of days during which mountain hares were a different colour than their surroundings.

This study was possible thanks to the #Scandcam project and used camera-trap data on mountain hares and their coat colour from almost 700 locations throughout Norway over a timespan of 8 years. Many students helped classify the mountain hare images into three categories: brown, white, and moulting.

The initial results suggest that European polecat has increased in body mass the most, followed by pine marten and stoat. While several other species have remained relatively stable in mass. Next steps are to try to tease apart what the potential drivers are. #ecm9